Mother-Son Incest: Hidden in Shame and Rising

"There is this terrible stigma that boys crave sex," said Milligan. "We are just as impressionable and naive and just as afraid. How can anything be consensual at 4 or 11 years old?"

He was finally able to tell all in the self-published memoir he took a decade to write -- initially titled "God Must Be Sleeping," he changed the title to reflect a more upbeat chronicle of his survival, "A Beautiful World."

But Milligan has much to be positive about. Though his childhood was ravaged, he has managed to raise a son, now 23, who "has never known violence or abuse."

About 10 percent of all crisis calls to the RAINN hotline are from males, according to program director Jennifer Wilson, who said they get about 100,000 calls a year.

"This crime is hard to track because people just don't share it with law enforcement," she told ABCNews.com.

In September, when child star MacKenzie Phillips went on the "Oprah Winfrey Show" to disclose her father had raped her at the age of 19, calls to RAINN's hotline from incest victims "spiked."

Mothers who sexually abuse tend to have higher rates of mental illness and are often the victims of abuse themselves. They also have easier access to children.

"It's easy for women to go unnoticed," said Wilson. "And at the legal stage, they get lighter sentences."

Because incest is considered taboo, few boys come forward and social service providers are not often trained in detecting signs in women abusers.

Abused As Child, Abuse as an Adult

One victim, Dominic Carter, a TV news reporter in New York, wrote about his own abuse at the hands of his mother in his 2007 memoir, "No Momma's Boy." Earlier this month, Carter was convicted of attempted assault after a 2008 fight with his wife, and could face up to three months in jail.

As a child, Milligan turned his anguish inward.

"My brother and sister could leave the house and naturally play with friends," he said. "I was petrified to leave mother. The clear sense was that if I did, the punishment would be worse."

His mother also threatened to kill herself and Milligan said he more than once was hit by cars while chasing his mother into the street.

His father was equally volatile, returning once to beat his mother "so bad he left her with an eye hanging out of the socket."

Teachers were also unaware of the abuse. "In their defense, I was kept out of school," he said about his frequent injuries. "My mother was very cunning."

The family was on welfare, but when social service workers paid their visits, the children were "always pushed out of the house and not allowed to come home," Milligan said.

"Most kids have normal exams, and most parents give a credible history," she said. "Most prepubescent boys and girls don't have any lasting physical findings. Abrasions and redness disappear within 24 hours of the event."

For young children, like Milligan, who eventually called an older married sister to intervene, getting help is difficult.